QuestionI have a 78 mgb that won't start. It turns over with no hesitation but will not start. What I have done is 1) replaced the fuel pump, fuel flow is good, 2)checked that the starter and ignition relays work 3) installed a new coil, checked that power is getting to the coil and plugs.
Any help is greatly appreciated.
sb
AnswerHi Seth,
All gasoline engines only require 3 items to run with conditions on each.
Compression --- 125 to 180 PSI on all cylinders. (must be tested with the throttle open)
This is the FIRST test and if it fails this test, it is a waste of time checking the other two.
Fire ------ This is spark and it must be able to jump at the plug wire at least 3/8 inch and must be thick and blue in color. The spark must be at the correct time (timing)
Fuel ------ This must be a combustible fuel and available to the combustion chambers and at close to the correct air/fuel ratio. This is easy to test if the first two items are correct by just spraying starter fluid into the intake when trying to start the engine. If it didn't start with the first two correct and does start with starter fluid, you for sure have a fuel problem.
One last test should be done and that is a manifold vacuum test. (throttle closed) If you have vacuum at first few turns and the vacuum dies off to zero, you have a completely stopped up exhaust system.
let me know, and stop buying parts until you know what is wrong.
Howard
